iio: imu: kmx61: Enhance error handling

This fixes parts of kmx61 error handling to make code easier to read and to be
more consistent with IIO coding conventions:
	* prefer as single point for error handling instead of duplicating code
	for each function
	* directly return a value from a case branch instead of breaking
	* fix error message for writing REG_CTRL1

Also, add separate error paths for kmx61_trigger_setup/iio_triggered_buffer_setup
calls.
Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/imu/kmx61.c

@@ -656,11 +656,7 @@ static int kmx61_setup_new_data_interrupt(struct kmx61_data *data,
 		return ret;
 	}
 
-	ret = kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG, true);
-	if (ret)
-		return ret;
-
-	return 0;
+	return kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG, true);
 }
 
 static int kmx61_chip_update_thresholds(struct kmx61_data *data)
@@ -678,12 +674,10 @@ static int kmx61_chip_update_thresholds(struct kmx61_data *data)
 	ret = i2c_smbus_write_byte_data(data->client,
 					KMX61_REG_WUF_THRESH,
 					data->wake_thresh);
-	if (ret < 0) {
+	if (ret < 0)
 		dev_err(&data->client->dev, "Error writing reg_wuf_thresh\n");
-		return ret;
-	}
 
-	return 0;
+	return ret;
 }
 
 static int kmx61_setup_any_motion_interrupt(struct kmx61_data *data,
@@ -737,11 +731,7 @@ static int kmx61_setup_any_motion_interrupt(struct kmx61_data *data,
 		return ret;
 	}
 	mode |= KMX61_ACT_STBY_BIT;
-	ret = kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG, true);
-	if (ret)
-		return ret;
-
-	return 0;
+	return kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG, true);
 }
 
 /**
@@ -924,15 +914,13 @@ static int kmx61_read_event(struct iio_dev *indio_dev,
 	switch (info) {
 	case IIO_EV_INFO_VALUE:
 		*val = data->wake_thresh;
-		break;
+		return IIO_VAL_INT;
 	case IIO_EV_INFO_PERIOD:
 		*val = data->wake_duration;
-		break;
+		return IIO_VAL_INT;
 	default:
 		return -EINVAL;
 	}
-
-	return IIO_VAL_INT;
 }
 
 static int kmx61_write_event(struct iio_dev *indio_dev,
@@ -950,15 +938,13 @@ static int kmx61_write_event(struct iio_dev *indio_dev,
 	switch (info) {
 	case IIO_EV_INFO_VALUE:
 		data->wake_thresh = val;
-		break;
+		return IIO_VAL_INT;
 	case IIO_EV_INFO_PERIOD:
 		data->wake_duration = val;
-		break;
+		return IIO_VAL_INT;
 	default:
 		return -EINVAL;
 	}
-
-	return IIO_VAL_INT;
 }
 
 static int kmx61_read_event_config(struct iio_dev *indio_dev,
@@ -978,7 +964,7 @@ static int kmx61_write_event_config(struct iio_dev *indio_dev,
 				   int state)
 {
 	struct kmx61_data *data = kmx61_get_data(indio_dev);
-	int ret;
+	int ret = 0;
 
 	if (state && data->ev_enable_state)
 		return 0;
@@ -987,27 +973,25 @@ static int kmx61_write_event_config(struct iio_dev *indio_dev,
 
 	if (!state && data->motion_trig_on) {
 		data->ev_enable_state = 0;
-		mutex_unlock(&data->lock);
-		return 0;
+		goto err_unlock;
 	}
 
 	ret = kmx61_set_power_state(data, state, KMX61_ACC);
-	if (ret < 0) {
-		mutex_unlock(&data->lock);
-		return ret;
-	}
+	if (ret < 0)
+		goto err_unlock;
 
 	ret = kmx61_setup_any_motion_interrupt(data, state, KMX61_ACC);
 	if (ret < 0) {
 		kmx61_set_power_state(data, false, KMX61_ACC);
-		mutex_unlock(&data->lock);
-		return ret;
+		goto err_unlock;
 	}
 
 	data->ev_enable_state = state;
+
+err_unlock:
 	mutex_unlock(&data->lock);
 
-	return 0;
+	return ret;
 }
 
 static int kmx61_acc_validate_trigger(struct iio_dev *indio_dev,
@@ -1066,8 +1050,7 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 
 	if (!state && data->ev_enable_state && data->motion_trig_on) {
 		data->motion_trig_on = false;
-		mutex_unlock(&data->lock);
-		return 0;
+		goto err_unlock;
 	}
 
 
@@ -1077,10 +1060,8 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 		device = KMX61_MAG;
 
 	ret = kmx61_set_power_state(data, state, device);
-	if (ret < 0) {
-		mutex_unlock(&data->lock);
-		return ret;
-	}
+	if (ret < 0)
+		goto err_unlock;
 
 	if (data->acc_dready_trig == trig || data->mag_dready_trig == trig)
 		ret = kmx61_setup_new_data_interrupt(data, state, device);
@@ -1088,8 +1069,7 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 		ret = kmx61_setup_any_motion_interrupt(data, state, KMX61_ACC);
 	if (ret < 0) {
 		kmx61_set_power_state(data, false, device);
-		mutex_unlock(&data->lock);
-		return ret;
+		goto err_unlock;
 	}
 
 	if (data->acc_dready_trig == trig)
@@ -1098,10 +1078,10 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 		data->mag_dready_trig_on = state;
 	else
 		data->motion_trig_on = state;
-
+err_unlock:
 	mutex_unlock(&data->lock);
 
-	return 0;
+	return ret;
 }
 
 static int kmx61_trig_try_reenable(struct iio_trigger *trig)
@@ -1207,7 +1187,7 @@ static irqreturn_t kmx61_event_handler(int irq, void *private)
 	ret |= KMX61_REG_CTRL1_BIT_RES;
 	ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_CTRL1, ret);
 	if (ret < 0)
-		dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
+		dev_err(&data->client->dev, "Error writing reg_ctrl1\n");
 
 	ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_INL);
 	if (ret < 0)
@@ -1409,15 +1389,17 @@ static int kmx61_probe(struct i2c_client *client,
 		data->acc_dready_trig =
 			kmx61_trigger_setup(data, data->acc_indio_dev,
 					    "dready");
-		if (IS_ERR(data->acc_dready_trig))
-			return PTR_ERR(data->acc_dready_trig);
+		if (IS_ERR(data->acc_dready_trig)) {
+			ret = PTR_ERR(data->acc_dready_trig);
+			goto err_chip_uninit;
+		}
 
 		data->mag_dready_trig =
 			kmx61_trigger_setup(data, data->mag_indio_dev,
 					    "dready");
 		if (IS_ERR(data->mag_dready_trig)) {
 			ret = PTR_ERR(data->mag_dready_trig);
-			goto err_trigger_unregister;
+			goto err_trigger_unregister_acc_dready;
 		}
 
 		data->motion_trig =
@@ -1425,7 +1407,7 @@ static int kmx61_probe(struct i2c_client *client,
 					    "any-motion");
 		if (IS_ERR(data->motion_trig)) {
 			ret = PTR_ERR(data->motion_trig);
-			goto err_trigger_unregister;
+			goto err_trigger_unregister_mag_dready;
 		}
 
 		ret = iio_triggered_buffer_setup(data->acc_indio_dev,
@@ -1435,7 +1417,7 @@ static int kmx61_probe(struct i2c_client *client,
 		if (ret < 0) {
 			dev_err(&data->client->dev,
 				"Failed to setup acc triggered buffer\n");
-			goto err_trigger_unregister;
+			goto err_trigger_unregister_motion;
 		}
 
 		ret = iio_triggered_buffer_setup(data->mag_indio_dev,
@@ -1445,14 +1427,14 @@ static int kmx61_probe(struct i2c_client *client,
 		if (ret < 0) {
 			dev_err(&data->client->dev,
 				"Failed to setup mag triggered buffer\n");
-			goto err_trigger_unregister;
+			goto err_buffer_cleanup_acc;
 		}
 	}
 
 	ret = iio_device_register(data->acc_indio_dev);
 	if (ret < 0) {
 		dev_err(&client->dev, "Failed to register acc iio device\n");
-		goto err_buffer_cleanup;
+		goto err_buffer_cleanup_mag;
 	}
 
 	ret = iio_device_register(data->mag_indio_dev);
@@ -1475,18 +1457,18 @@ static int kmx61_probe(struct i2c_client *client,
 	iio_device_unregister(data->mag_indio_dev);
 err_iio_unregister_acc:
 	iio_device_unregister(data->acc_indio_dev);
-err_buffer_cleanup:
-	if (client->irq >= 0) {
-		iio_triggered_buffer_cleanup(data->acc_indio_dev);
+err_buffer_cleanup_mag:
+	if (client->irq >= 0)
 		iio_triggered_buffer_cleanup(data->mag_indio_dev);
-	}
-err_trigger_unregister:
-	if (data->acc_dready_trig)
-		iio_trigger_unregister(data->acc_dready_trig);
-	if (data->mag_dready_trig)
-		iio_trigger_unregister(data->mag_dready_trig);
-	if (data->motion_trig)
-		iio_trigger_unregister(data->motion_trig);
+err_buffer_cleanup_acc:
+	if (client->irq >= 0)
+		iio_triggered_buffer_cleanup(data->acc_indio_dev);
+err_trigger_unregister_motion:
+	iio_trigger_unregister(data->motion_trig);
+err_trigger_unregister_mag_dready:
+	iio_trigger_unregister(data->mag_dready_trig);
+err_trigger_unregister_acc_dready:
+	iio_trigger_unregister(data->acc_dready_trig);
 err_chip_uninit:
 	kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
 	return ret;